(Maint) rubyw.exe is broken in ruby 1.9

Previously, the mcollective batch file when bundled into puppet, would
invoke rubyw to run mcollective. If mcollective were to ever use Ruby's
built-in process handling, e.g. %x, and attempt to read stdout/stderr of
a child process it would fail due to http://bugs.ruby-lang.org/issues/7239.

This commit just updates the batch file to invoke ruby.exe, which does
not have this problem, because ruby.exe is a console application and
always allocates a windows console.